There are many ways to practice the sevenfold rod exercise. You can repeat it three, four, seven, or twelve times. The important thing is that it is not a mechanical repetition, but every time a new experience.

I would suggest that you repeat the exercise quietly seven times, each time addressing a different, deeper layer of your body sensation. Like the seven bowls of an onion. The fourth time, the middle of the seven times, you can try to experience with a quality similar to a heart quality.

If you get the impression of each time getting a tiny bit taller just by itself, then you know you're on the right track.